Carburetor



Nov. 17. 1925.

| SAlVES CARBURETOR Filed April 20. 1922 2 Sheets-Sheet 1 INVENTOR ATTORNEY L. SAIVES CARBURETGR Filed AprzIl 20. 1922 Nov. 17, 1925 2 Sheets-Sheet 2 Fig.2

: I l I l I I INVENTOR ATTORNEY Patented Nov. 17, 1925.

, UNITEDVSTATES PATENT OFFICE.

LEON SAIVES, OF BILLANCOURT, FRANCE, ASSIGNOR TO LOUIS RENAULT, OF

. BILLANCOURT, FRANCE.

GARBURETOR.

Application filed April 20,

T 0 all 1072 am it may con/awn:

Be it known that I. LrioN vSArvEs, engineer, citizen of the French Republic, residing at Billan'court. Department of the Seine. in France, and whose P. 0. address is 15 Rue Gustave Sandoz.' in the said city, have invented certain new and useful. Improvements in or Relating to Carburetors; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to an improved carburetor for internaLcombustion engines and is illustrated in the accompanying drawings, in which Fig. 1 is a vertical section on line 11 of Fi 2.

Fi 2 is a vertical section on line 22 of Fig. 1.

Fig. 3 is a vertical section on line 33.

of Fig. 1.

Fig. 4 is a vertical section of a modified form.

Fig. 5 is a similar view of a further modified form. V

Referring to Figs. 1, 2 and 3 of the drawings, 1 indicates the body. of the carburetor provided with an end flange 2' for the purpose of attaching the carburetor to the en'- gine. The discharge end of the carburetor comprises a generallycylindrical chamber 4' in which is mounted a butterfly valve 5 controlling the cross sectional area of the passage of the gases to the engine. The forward end of the body portion is bell-shaped, as at 3. the opening being protected by a hood 4, the s ace between the hood and the rim of the ell-shaped opening constituting the main air inlet to the carburetor.

Rigidly secured to a rod 7 mounted in the perforated boss in the hood 4. is a Venturi tube 6, which is thus mounted for axial adjustment in the flaring end 3 of the carburetor, so that the inner edge of said Venturi tube cooperates with the walls of the inner end of the'flaring opening 3 to open and close a passage for air to the carburetor, outside of saidVenturi tube. The rod 7 is preferably connected to the accelerator button or pedal, as will be understood. A nozzle 8 communicating with a constant level fuel feed chamber is mounted in the lower side of the carburetor with its discharge end 1922. Serial No. 555,763.

extending through a slot 9 in the lower side of the Venturi tube 6.

In the body of the carburetor and adjacent the minimum diameter of the ,flaring'end 3 thereof is an annular duct 11 provided with a series of openings 10 communicating with inner end of the Venturi tube 6. The duct 11 is connected to the constant level feed chamber by an inverted U-shaped passage 12 having a return bend 13, in the leg of which adjacent the constant level feed chamberthere is located a restricted opening 14. An air inlet tube 15 extends into the passage 13 and terminates at a point above the, restricted opening 14, as shown in Fig. 3.

The interior of the body portion 1 is provided with an annular flange 16, to the rear of which is fixed a second Venturi tube 17 mounted in passage 4, the flange 16 and the interior wall of the Venturi tube 17 constituting an annular passage 18, which communicates with an automatic air valve 20 mounted on one side of the carburetor, the communication being established by means of a hood 19.

The action of the carburetor, as described, is as follows: At low speeds of the motor, the Venturi tube 6 occupies the position shown in Fig. 1 with its inner edge engaging the walls of the flaring end 3, and the discharge end of nozzle 8 projecting into the restricted portion of the Venturi tube 6 where the suction is greatest. The airentering the space between the flaring end 3 of the body 1 and the hood 4 is drawn through the bore of the Venturi tube and entrains the fuel delivered by nozzle 8, themixed air and fuel passing through .the opening formed by the flange 16, thence through the second the interior of the flaring end 3 adjacent the i I Venturi tube 17, where an additional supply of air isdelivered to the mixture by way of air valve 20, the hollow hood 9 and the passage 18 formed between the flange 16 and the interior, of the Venturi tube 17, this auxiliary air supply being automatically controlled in accordance with the suction, which is dependent upon the speed of the engine. When the engine is to be operated at normal and high speeds, the. rod 7 is actuated to withdraw the Venturi tube' 6 from its seat opening a direct communication for the air on the outside of the Venturi'tube, so that against the walls of the restricted throat of the section 3 of the body portion, thereby this entering air will entrain the fuel delivered by the annular series of openings 10,

i thereby augmenting the fuel supply from "tube, it will be apparent that the slight diminution in the fuel supply in the nozzle 8 will occur when the Vent'uri tube 6 is retracted by the rod 7 to bring the second fuel sup plied by way of the annular series of jet openings 10, into action. However, the C0111- bined fuel supplied from the jet nozzle 8 and the annular series of openings 10 is adequate to operate the engine at normal speeds and obviously the speed may be increased by adjusting the Venturi tube outwardly in the flaring throat 3 of the carburetor, thereby increasing the opening between the Venturi tube and the walls ofthe flaring opening, so that a large volume of air passes into the carburetor outside of the Venturi tube 6 and entrains larger portions of fuel from the annular series of openings 10. In the particular modification shown in Fig. 4, the

' carburetor is arranged vertically, the Venturi tube 6 being actuated by the rod 7 connected to the accelerator pedal or button and the jet nozzle 8 being in axial alignment with the opening through the Venturi tube. The operation of this device is practically identical with that of the carburetor first described.

In the modification shown in Fig. 5, the

same general arrangement is followed as in Fig. 4, except that the lower portion of the Venturi tube 6, which latter is guided in the nular series of openings 10 during normal or high speeds. The openings 21 admit the air outside of the Venturi' tube, when the latter has been displaced, said air sweeping over the openings 10 and carrying the fuel from said openings into the body portion of the carburetor.

"What I claim is:

A carburetor for internal combustion engi 'ies comprising a casing having a longitudinal bore, said bore being enlarged adjacent one end to form an air chamber, a Venturi tube axially movable in said air chamber serving as a primary air inlet and controlling communication between said air chamber and said bore, means for discharging fuel into said Venturi tube, means for discharging fuel in to said air chamber adjacent said Venturi tube, a second Venturi tube fixed within said bore in the rear ofsaid adjustable Venturi tube, an auxiliary air chamber communicat ing with said bore between said Venturi tubes, and suction responsive means for controlling the supply of air to said auxiliary air chamber.

In testimony whereof I afix my signature.

LEON SAIVES. 

